In this paper we outline a typology, which will be useful for those engaged in the design and customization of information systems in healthcare. Drawing on ethnographic case studies conducted in six healthcare settings in two countries, the typology outlined here is intended to identify possible sources of local variability of health care work practices, which need to be accommodated in local configurations of generic information systems. Author Keywords Health informatics, ethnography, work practice, computer supported cooperative work. ACM Classification Keywords J3. Life and medical sciences: medical information systems; K4.3. Organizational impacts: computer-supported collaborative work